<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <p>1</p>
    <p>2</p>
    <p>3</p>
    <script>
        //数组去重[1,2,3,1]
        console.log([...new Set([1, 2, 3, 1])]); //[1,2,3]
        //字符串去重 'aaabccb'
        console.log([...new Set('aaabccb')].join(' ')); //a b c
    </script>
</body>

</html>